Flora of North America species comparison

leaves triangular-ovate, more than 1.2 mm, usually appressed;

apex acute to apiculate, hyaline cells rarely septate or porose, apical region often fibrillose.

leaves triangular-lingulate to lingulate, 0.7–1.4 mm;

apex rounded-obtuse and weakly denticulate;

hyaline cells nonseptate, mostly efibrillose, and, if porose, with more pores per cell on the concave surface (3–6) than on the convex surface (0–2).

mostly unranked to weakly 5-ranked, often conspicuously falcate, leaves greatly elongated at distal end.

somewhat curved, leaves spreading.

ovate-lanceolate to lanceolate, 1.6–5 mm, falcate toward branch tips, when dry often undulate and recurved, rarely weakly serrulate along the margins in submerged forms, leaves from middle of spreading branches with length to width ratio less than or equal to 1:0.28;

hyaline cells length to width ratio in apical convex surface region 8:1 or more, convex surface with 0–1 small round pores at apex, concave surface with faint round wall thinnings in cell apices and angles; chlorophyllous cells triangular to trapezoidal in transverse section, broadly exposed on the convex surface and exposed slightly on the concave surface.

ovate to ovate-lanceolate, 1.2–2 mm;

subsecund;

hyaline cells with numerous tiny pores in a continuous line along the commissures on the convex surface, no or scattered pores on the concave surface.

dioicous.

dioicous.

exserted, with scattered pseudo-stomata.

29–38 µm; covered with large papillae on both surfaces, appearing pusticulate;

proximal laesura less than 0.5 spore radius.

22–28 µm;

papillose on both surfaces;

proximal laesurae more than 0.5 spore radius.

fascicles with 2 spreading and 2–3 pendent branches.;

branch stems green, but often pinkish at the proximal ends, with cortex enlarged with conspicuous retort cells.

fascicles with 2–3 spreading and 2–3(4) pendent branches.